Kills all types of weeds (as listed) without harming your lawn (when used as directed). The formula is rainproof in 1 hour and is fast-acting with visible results in just one application. It kills over 200 weeds down to the roots, including dandelion, chickweed, clover, crabgrass, and foxtail. For use on grasses, including Bermudagrass, Buffalograss, Fescues, Kentucky Bluegrass, Ryegrass, and Zoysiagrass. Apply when weeds are small and actively growing in the spring or fall. For crabgrass, apply in the spring before it is 4 inches tall or when it is first noticeable in the lawn.